Focusing device for semaphore lamps



May 14, 1929. 1 s. M, DAY 1,713,490

FOCUSING D EVICE FOR SEMAPHORE LAMPS Filed March 10, 1923, 2 Sheets-Sheet 1 j/ jyvla R I Z/ ,ZTTORNEY Patented May 1 ,1925. i 1,713,490. UNITED STATES PATENT OFFICE- SALISBURY M. nAYfor nocnns'rnn, NEW YORK, ASSIGNOR r GENERAL RAILWAY SIGNAL COMPANY, or GATES, NEW YORK, A CORPORATION or NEW YORK.

FOCUSING DEVICE FOR SEMAPHORE LAMPS. v Application filed March 10, 1923. Serial No. 624,268. This invention relates to electrically lighted semaphore lamps or the like used for. railway signaling purposes, and more partlcularother source, to. this proper point. More specifically, this focusing device comprises facilities are afforded.

ly to an adjustable supportfor the lamp bulb, in conjunction with suitable means for determining when theluminous center of the filament of the l amp is properly located with respect to the lens or light concentrating device.

Incandescent lamps, especially of'the concentrated filament type, when used in color light signals or in semaphore lamps, require such filaments to belocated substantially at the focus of the lens or other light concentrating device, in order to properly concentrate and direct the light into a beam of the desired spread. Incandescent lamps of this kind, however, when manufactured in quantity and on a commercial scale, do not have their filaments definitely located with respect to the lamp bases. WVhen it becomes necessary to replace a burnt out lamp, therefore, it

is not possible to obtain eflicient results with-.

out in some way adjusting the socket or support for the lamp so as to bring the filament of the new lamp in the correct position. The making of suchan adjustment in the-field each time a lamp is replaced is an involved and tedious operation, unless special tools or Ordinarily, the services of two skilled operators are required, one at .the signal to make another at a distance to determine from the appearance of the signal when the correct adjustment has been made.

lVith these and other considerations in mind, the primary object of the present invention is to provide a lamp support or mounting for the electric lamp of semaphore signals or of color light signals, this support being easily and quickly manipulated so as to focus the filament of a lamp properly with respectto the lens. Generally speaking, it is proposed in accordance with this invention to provide a simple and inexpensive lamp support, which is adjustable in three different planes and in which any one of these adjustments may be made without disturbing any one of the other adjustments. The invention further contemplates the provision of a focusing device, by which the correct point for the loration of the filament with respect to the lens may be readily determined and by the aid of which the lamp support may be adjusted so as to bring the concentrated filament, or

the adjustments and an optical apparatus which may be quickly and positively positioned in a definite relation with respect to the lens or other light concentrating deviceand which afl'ords two sighting lines converging .from difi'erent points and intersectingat'the proper point for the location of the filament, so that by adjustment of the lamp to bring its filament on the point of intersection of these sighting lines, it is assured that this filament is in the proper relation with respect to the lens. 7 A

Other objects, purposes and characteristic features of the invention will appear as the description thereof progresses.

In the drawings has been shown one embodiment of the invention to which reference will be made in the following description, and in which Fig. 1 illustrates a front view of a lamp casing for a semaphore signal for railways andwhich shows a bracket in dot and dash lines on which the casing is supported;

Fig. 2 is a vertical longitudinal sectional elevation of the device shown in Fig. 1 and shows the construction of the adjustable lamp 7 support;

Fig. 3 isa horizontal sectional view taken on the line 3-3, Fig. 4, as viewed in the direction of the arrows, and shows the lam hon with the cover removed and with the focusing device located in its operative position Fig. 4'is a sectional elevation taken on the line 4-4, Fig. 3, as viewed 1n the direction of the arrows; and w l ig. 5 1s a rear elevation of the focusing dev ce shown in Flgs. 3 and 4 in operative position, a portion of the lamp casing being roken' away.

IT lgrb. h

in (0.0.1 ing t e invention in with a large circular opening countersunk to m v detail, the signal lamp casing and the adjustable socket lamp tobe used This lower part casing, which receives the form a for a lens 5, tlis lens being held in place by a bezel'ring 6 fastened to said front wall by bolts 7. ALE-shaped gasket 8 around the edge of the lens protects it from severe pressure at local points, and also tightly closes the casing against ingress of dirt and moisture. o I

The lamp casing C is designed to be supported in the manner now commonly used upon a U-shaped bracket 9, shown in dot and dash lines in Fig. 1, this bracket being attached inpractice to the mechanism casingv of the semaphore signal. While the lamp casing G maybe supported or mounted in thcr fashions, in the construction Sll( vn, on one side the lamp casing-.C is an integral guide-lug 10 (see Fig. 1) formed with a lone hole to receive the upstanding leg of the supporting bracket 9; and near the other side of the lampcasing is a downwardly projecting notched lug 11, preferably integral with the upper end of the other leg of said bracket. Aset screw 12 passing through the side wall '8 serves to clampvthe lamp casing tightly in position.

The cover 15 for the lamp casing G is rounded, as best shown in Fig. 1, and is shaped so that its edges all around overlap the edges of the lower portion of said casin as shown in Fig 2. A downwardly projecting flange 16 on the cover 15 hooks over the front wall of the casing C; and the rear end of this cover is held in place bya hasp member 17 and staple 18, as shown in Fig. 2', a padlock through said staplebeing used if desired to prevent the casing being opened by unauthorized persons.

V In the rear wall of the cover 15 is a small opening covered bya small lens or bulls eye 19, clear or colored as preferred, whiclris held in place by a bezel ring 20 screw fastened to the cover by screws 21. Thisopening and lens 19 provide an auxiliary signal or rear light, so that the presence of an illuminated lamptherein may be observed from therear.

To the top of this cover C is riveted a suitable handle 22. e

In the bottom of the casing is fastened an insulating block by screws 26. On this block is screw fastened a metallic plate 27 by wood screws 28. This plate is provided with upstanding threaded studs 29 provided with nuts 30. Supported on this plate 27 is a base plate or foot 82, having an upstanding square shank 33 forming a pedestal This base plate 32 of the pedestal is provided with long slots through which the threaded studs 29 pass, thus facilitating adjustment of the pedestal toward and away from the lens 5, as clearly illustrated in Fig. 3. After such adjustment has been made the nuts may be tightened, thereby holding the pedestal in place.

Supported on the square shank 33 so as to slide up and down but not turn is a cylindrical sleeve 35, having an outwardly extending "lange at the lower end thereof. This sleeve 35 is provided with a set screw 37 and lock nut 38, so that the sleeve may be adjusted to any desirable height and perinanently locked in this'position. Pivotally sup ported on the sleeve 35 and resting on the flange 36 is a bracket l0. The bearing portion of this bracket 40 extending around the sleeve 35 is slotted radially, and is drilled crosswise of this radial slot and provided with a'screw 42 by which this bearing portion may lie-firmly clamped on the sleeve 35.

On the extreme end of the bracket 40 is nounted' alamp receptacle R, comprising an insulating block A- having a socket shell ll) fastened thereto and provided with a suitable center contact (not shown). This socket shell 45 may be of the screw type shownor of the bayonet slot type. The socket shell l5 and center contact are connected to suitable connecting or binding posts a6 and 47 respectively (see Fig. These binding posts comprise U-shaped metallic members whichare screw fastened to 'the insulating block 25, and are provided with clamping scre and washers 48 for facilitating the attaclnnent'of the wires of the lighting circuit.

In this socket shell 45 is supported an incandescent lamp 50 provided with two concentrated filaments 5 and 52 located close together and connected in multiple. This arrangement of two filaments in multiple is provided so that if one of them burns out, the other may still serve its purpose but to an inferior eXtent,so that it may be noticed by the trainmen that the lamp should be replaced.

The socket shellaS maybe adjusted in three different directions substantially at right angles to each other. Sidewise adjustment is accomplished by loosening the screw 42 of the swinging bracket, thereby-. permitting said bracket and the lamp socket thereon to be swung sidewise in either direction. Vertical adjustment is obtained by loosening the set screw 37 and sliding the sleeve 35 up or down to the desired point on the shank 33. Finally, forward and backward adjustment to vary the distance of the lamp receptacle from the lens 5 may be changed by loosening the'nuts 30 and shifting the base 32 of the pedestal to the desired position on the metallic plate 27.

lhe purpose of these adjustments is'to al filament of any lamp to be brought in the proper position to cooperatewith the lens and give the desired light distribution. Such adjustments, therefore, permit lamps of commercial manufacture, with the locations of their filaments varying with respectto their bases, to be used with any lamp.

In addition to such adjustability, however, it is also desirable for use in practice to have a simple and effective method of ascertaining when the filament has been brought to the proper position or on focus, as this relation may be conveniently expressed. .One way of telling if the filament is on focus is to look at the signal from a distance while the lamp is moved around, noting which particular position of the lamp gives the strongest indication for the signal. t vill be evident, however, that such a method of procedure requires the close cooperation of at least two skilled operators, one at the signal to make the changes and adjustment, and the other an experienced observer-at a distance from the signal, there being also required in addition some effective scheme of communication between these operators. It will be evident that such a method is not well suited for practical use.

It will. bereadily recognized. however, that there is a certain definite position of the filament with respect to the lens which gives the most effective indication. This position can be accurately ascertained or predetermined during manufacture, and is the same for all lenses of the same structure. One important feature of this invention is the provision of a sighting or focusing attachment by which the same operator at thesignal may easily tell when the filament is in the proper position after he makes various adjustments or changes in the position of the particular lamp then in the socket. V 1

Referring more particularly to Figs. 3, 4

and 5, this focusing devicegenerally speaking, comprises a sighting device and an ar' raugmnent for supporting this sighting device in a definite relationto the lens 5. More specifically. this focusing device comprises aniuverted U-shaped bracket (see Fig. 5), having its lowerend bifurcated to straddle the snallow rear wall 2 of the casing C, thumb screws 56 beingprovided for clamping this bracket in place. This bracket 55 is provided with a pair of bosses on the op posite side thereof, which are drilled out to form bearings for slidably supporting the tubes 57 and 58 of the sighting devices. These tubes are rigidly fastened in holes in the base member 60 of the sighting device. This base member has three diverging arms in which are fastened feelers or pilot rods 61, 62 and 63, snugly fitting in holes in these arms, and

maintained rigidly therewith by pins 64:. These pilot rods are notched near the r free ends to cooperate with the outside circular ridge of the lens-5, and'form a three-point bearing to accurately determine the relation of the sighting device to the lens. Theserods 61-63. are preferably slightly resilient and tend tospread apart at their outer ends so as to be held snugly in place on the lens.

The tubes 57 and 58 have their free ends connected together by a sighting piece 65, which-is provided with countersunk bosses extending into the tubes, and is maintained in this position by screws 66. Two small holes 67 are drilled in the sighting piece to-lineup substantially with the center of the countersunk bosses, and therefore lin ing up with the axis of the tubes 57 and 58 to form peep holes which line up with similar peep holes-68 in the base member 60 at the other end of the tube, thus providin a closely defined line ofvision through the tu es 57 and 58. If desired, the holes 68 may be made larger and provided with glass panels, each having suitable sightingmarks,such as, crosses or circles thereon. This construction would allow a larger field of vision, and would at the same time afford accurate locationof the luminous center of the filament. The tube 58 is surrounded by a compression coil spring 70, which urges the base member 60 away from the bracket 55. This base member 60 has integral therewith a forwardly projecting arm 71 terminating in an oblique portion and disposed substantially at an angle of 45 degrees to the line of sight through the tube 57. A mirror 72 is suitably attached to the oblique portion of the arm 71, being shown.

as set in a recess in a block 73 fastened to said arm and held in place by a bezel ring 74 secured in place by screws. It will thus be noted that the line of vision through the tube 57 is diverged at the mirror 72 in a di' rection substantially at right angles to the line of vision through either of the tubes 57 and 5S, and that the lines of vision through these two tubes intersect, and therefore determine a point in the same plane, that is, a definite point with respect to the sighting device and pilot rods 61, 62 and 63.

0perati0n.Assume that the lamp as 50in the signal casing burnsout, and that it is desired to replace this lamp by another one which has been manufactured on the usual commercial basis, and which presumably has its filament located differently with respect to its lamp base than the lamp burnt out. After inserting the new lamp in the socket shell 45 in the usual way, the focusing attachment is then applied to the lamp casin In doing this, the three pilot rods 61, 62 and 63 are set with their notched ends on the outer ridge or step of the lens 5, the bracket 55 being pressed inward at the same time and set on the outer rear wall of the lamp casing C. After such adjustment as may be necessary to bring all of the rods 6l63 properly seated and determining the position of. the

member 601 andthe sighting tubes 57 nd the thumb screws. 56 are set up to hold the sighting device firmly in position. In this way, the sighting tubes 57 and 58 are set accurately in a definite relation to the lens 5, irrespective of variations inL the casin These tubes then define sighting lines intersecting at the point. where the filament, or rather its. luminous center, should be located for the most eflicient results. The tube 57 in, conjunction with the mirror 72 defines the distance between the lens and the proper point for the-filament, whereas the sighting tube 58 defines the position of the filament with respect to the axis of the lens.

After the focusing device has been properly used, the-filament may be lighted, if necessary, for observation, through the sighting tubes 57 and 58. Assuming that the filament of the new lamp is located differently with respect to its base than the burnt out lamp,

the operator will observe tha the luminous center of the new filament does not line up with the sighting apertures 1nthe tubes. 57

. and 58,, indicating that new adjustment of the lamp support is required. In making this adjustment, it is usually best to set the filament at the proper distance back from the lens, although in other instances itmay be desirable to line the filament up with the axis of the lens first. By loosening the. lock nuts 30, the base plate 82 may be shifted forwardly or rearwardly as conditions may be required, whereupon the nuts 30 may be tightened to hold the difi'erent plane of adjust ment.. By loosening the set screw 37, the sleeve '35 may be raised to the point to bring the filament in line with the sighting tube 58..

Similarly, the screw 42 and the swinging bracket may be loosened so that the bracket may be turned to shift the filament in a horizontal plane and bring it in the axis of the-lens.

The-various adjustments in the three planes may be made in differentorders as conditions may be required. Sometimes for most accurate results, it is necessary to make a new adjustment for one plane after a change in the adjustment for another plane; but ordinarily the proper adjustment in each of the three planes may be made in succession,.each

adjustment when made being undisturbed by subsequent adjustments in other planes. It should be understood, of course, that the sighting arrangement or focusing attaclr ment just described may be used with any particular adjustable mounting for the lamp and is not limited to the particular lamp mounting shown and described.

- Itis thus seen that by practicing the present invention, it is. possible to place a lamp which has its. filament inaccurately located with respect to its base into an adjustable lamp receptacle ina casing and determine the proper position of this lamp. receptacle to but the lens its if, all of which is accom-r plished by a compact readily detachable focusing device which facilitates the inter changing of lamps in the lielclby a single person in a convenient and economic manner.

Having thus shown; and describedou-e' spcciiie manner in which a lampqsocket may be adjustably sup .iorted in one nirticular type of casing, and a focusing device bywhich such lamp may be defimtelyloeated with respect to a lensin thiscasing. it is desired to be understood that various changes, modifications and adaptations of the specific disclosure may be made without departing from the spirit'and scope ofthe'invention or the means for performing thefunctions thereof.

\Vhat is desired to be secured by Patentof the United States, is::

1. In a light signal system for railways, the combination of acasinghaving'an i'ncandeseent lamp adjustably supported therein; of means for determining the adjustment of the filament of said lamp to a predetermined. point with respect to a light concentrating device in said casing, comprising, detachable means adapted to be supported in the casingand having a three-point engagement with said light concentrating device,

Letters and a sighting device rigidly connected to said detachable means;

2. In a light signal, system for railways according to the preceding claim, thesighting device providing two, intersecting accurately defined lines of vision substantially at right. angles to each other at the point of intersection. i j

V 3. In a light signal system for railways, the combination of a casing having a lamp receptacle adjustably supported therein; and of means for determining the desired adjustment of said receptacle when a particular lamp is locatedtherein, said adjustment being dependent upon the relation of the filament of said lampto the lamp base comprising,

an optical sighting device mechanically pothe center line'of said lens, of a supporting bracket, havingdownwardly projecting legs bifurcated at thelr ends to straddle said rear wall, means for clamping said legs to said wall, and a sighting device slidably support ed in said bracket and yieldingly urged in contact with said lens.

the combination of a casing having a large opening in the front wall containing a lens, a sighting device having means for making a three point contact with said lens so as to assume a definite and predetermined relation therewith, means including a spring for urging said sighting device toward said lens, and means for clamping said last mentioned means to said casing.

6. In a light signal system for railways, the combination of a casing containing alight concentrating device and having an incandes-'- cent lamp adjustably supported therein; and of means for determining the point in the axis of said device at which the filament of said lamp should be located to direct a beam of light of the desired spread comprising, detachable means adapted to have a three point engagement with said light concentrating device, and a sighting device rigidly connected to said last mentioned means.

7. In alight signal system for railways, the combination of a casing having a lens in one side thereof and having a lamp receptacle adjustably supported therein; and of means for determining the point at which the filament of a particular lamp must be located in said casing so as to be in the focus of said lens comprising, detachable means adapted to be supported in the casing and engage said lens at three equi-distant points from the axis thereof, and a sighting device fixed to said de tachable means and affording two lines of sight passing through said point at an angle to each other, said sighting device being posi tioned to the opposite side of said point from that of said lens, when said attachable means engages said lens.

8. A focusing device for adjusting lamps in signal casings comprising, a bracket adapted to be clamped to the signal casing, a pair of parallelly disposed sighting devices slidably supported in said bracket, means associated with one of said devices for deflecting the line of vision through said device substantially ninety degrees, and means for determining the spacial relation of said device with a light concentrating device in said signal casing.

9. The herein described method of adjusting a lamp socket for supporting an incandescent lamp so that its filament will be located definitely with respect to a lens, which consists in first determining the point at which the filament should be located by applying a mechanical measuring device directly to suitable points on the lens, then sighting through this device to determine said point in space, and then adjusting the lamp socket contained in the lamp so that the filament of said lamp is located at said point.

V candescentlamp adjustably support 5. In a light signal system for railways,

1 0. In alight signal system for railways, the combination with a casing havin an m there in; of apparatus for adjusting the filament of said lamp with respect to alight concentrating 'device comprising, detachable means contacting with, and biased into a definite relation with respect to, said light concentrating device, and a sighting device rigidly connected to said means at a point remote from said concentrating device when said apparatus is in operative position.

11. A focusing device for adjusting lamps in signal casing so that the filaments assume a predetermined position regardless; of the exact relation of such filaments'of such lamps to their respective bases comprising, a bracket adapted to be clamped to a signal casing having a lens therein, a pair of sighting devices rigidly fastened together and slidably supported in said bracket having means associatcd therewith adapted to engage said lens, said sighting devices affording two lines of sight intersecting each other at the focus of said lens when said last mentioned means is in proper engagement with said lens.

12. In a focusing device of the character described, the combination of a signal lamp, with a main frame provided with means whereby the position of the illuminated element of the signal lamp may be determined relative to the intersection of a vertical and a horizontal axis, and means, secured to said main frame adapted to engage the lens of the signal lamp, said means being adapted to expand into'gripping relation with the lens, whereby the position of the main frame and its means relative to the center of the lens is automatically determined.

13. A focusing device, comprising a'frame provided with an eye-piece at one end, lens clamping means at the other end. the axes of the eye-piece and said means being aligned, means whereby said means may be moved into lens clamping position, another sighting tube secured to said frame, and reflecting means attached to the frame to afford a line of sight through said sighting tube intersecting the line of sight through said eye-piece.

14. In signaling apparatus of the type described, the combination with a light projecting unit comprising, a casing having a removable cover constituting the top and a portion of the rear wall of said casing, a lens in the front wall of the casing having steps on its inner face, and an incandescent lamp adjustably mounted in said casing; of a detachable focusing attachment for determining when the filament of said lamp is located at the focal point of the lens comprising, a main frame,.means secured to the main frame and engaging a step of said lens to position the main frame in a predetermined relation to main frame and defining lines of sight which intersect each other substantially at right angles at a point corresponding to the focal com n-ising, a casin-g, a lens with steps on itsv inner face supported in an opening in the front Wall of said casing with its axis subsl' anti'ally horizontal, an incandescent lamp, and adJnstahle means for supporting said lamp in-the casing and permitting ad usted movement of said lamp vertically and also adjusted movement independent of the vertical movement in any direction in a horizontal plane; and a focusing attachment for determining when said lamp has been ad1usted to position its filament at the focal point of the .lens ccm in'ising, a main frame, means on said main frame cooperating with :a step of the lens to position said frame 1n a predetermm-cd relation to the lens, a sighting device fixed to the main frame and defining a line of sight substantially coincident with the axis of the lens, and another sighting device fixed to said 7 main frame and defining a line of sight intersecting the first mentioned line of sight substantially at right angles and at .a point corresponding to the focal point of the lens when the main frame is positioned thereon.

1 6. A focusing"attachment for use With stepped lenses to indicate when the filament of an incandescent lamp is located-at the focal point of the lens andcomprising, a main frame, means secured to said main frame and adapt-ed to expand into engagement with a step on said lens at three places around its periphery, a sighting device fixed to the main frame and defining a line of sight along the aXisof the lens, and another sighting device including a reflecting surface and defining a reflected line :of sight in part in the same general direction as the first mentioned line of sight and in part intersecting said first mentioned line of sight "at the focal point of the lens.

, 17. In combination, a light signal having a casing, a light source and a lens, and a focusing device comprising a frame detachable from the casing, positioning means on the frame for engaging said lens, sighting means ri l ly fixed to the frame for determining the meal point of said lens when the frame is oroperly positioned in the casing, said sight ing means and said positioning means being on opposite sides of the point determined by said sighting means.

. In testimon Whereofl herebv afiix 1n si v C nature.

SALISBURY M. DAY. 

